A gauge R&R study was performed to compare two different ultrasonic methods used to measure wax pattern thickness in cored features in a turbine engine blade. The first measurement method used a handheld pencil style contact probe, while the second measurement method used through-transmission with a water squirter (aka bubbler or fountain) coupling. The objective of the study was to ascertain which method would produce the smallest measurement variation on certain features that had a history of measurement difficulty including core position and surface curvature. Neither method was found to be adequate for the purpose of quantifying dimensional process variation as most of the variation measured on these features was due to repeatability and reproducibility variation. For inspection purposes both methods were deemed marginally acceptable but only since they are redundant with other quality control checks.